Commit d74d2b22 authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash 



Replace the open coded PC relative offset calculations with adr_l and
ldr_l invocations. This removes some open coded PC relative arithmetic,
avoids literal pools on v7+, and slightly reduces the footprint of the
code. Note that ALT_SMP() expects a single instruction so move the macro
invocation after it.

Reviewed-by: default avatarNicolas Pitre <nico@fluxnic.net>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 59d2f282

arch/arm/kernel/sleep.S

+5 −14
Original line number Diff line number Diff line
@@ -72,8 +72,9 @@ ENTRY(__cpu_suspend) 
	ldr	r3, =sleep_save_sp

	stmfd	sp!, {r0, r1}		@ save suspend func arg and pointer

	ldr	r3, [r3, #SLEEP_SAVE_SP_VIRT]

	ALT_SMP(ldr r0, =mpidr_hash)

	ALT_SMP(W(nop))			@ don't use adr_l inside ALT_SMP()

	ALT_UP_B(1f)

	adr_l	r0, mpidr_hash

	/* This ldmia relies on the memory layout of the mpidr_hash struct */

	ldmia	r0, {r1, r6-r8}	@ r1 = mpidr mask (r6,r7,r8) = l[0,1,2] shifts

	compute_mpidr_hash	r0, r6, r7, r8, r2, r1
@@ -147,9 +148,8 @@ no_hyp: 
	mov	r1, #0

	ALT_SMP(mrc p15, 0, r0, c0, c0, 5)

	ALT_UP_B(1f)

	adr	r2, mpidr_hash_ptr

	ldr	r3, [r2]

	add	r2, r2, r3		@ r2 = struct mpidr_hash phys address

	adr_l	r2, mpidr_hash		@ r2 = struct mpidr_hash phys address



	/*

	 * This ldmia relies on the memory layout of the mpidr_hash

	 * struct mpidr_hash.
@@ -157,10 +157,7 @@ no_hyp: 
	ldmia	r2, { r3-r6 }	@ r3 = mpidr mask (r4,r5,r6) = l[0,1,2] shifts

	compute_mpidr_hash	r1, r4, r5, r6, r0, r3

1:

	adr	r0, _sleep_save_sp

	ldr	r2, [r0]

	add	r0, r0, r2

	ldr	r0, [r0, #SLEEP_SAVE_SP_PHYS]

	ldr_l	r0, sleep_save_sp + SLEEP_SAVE_SP_PHYS

	ldr	r0, [r0, r1, lsl #2]



	@ load phys pgd, stack, resume fn
@@ -177,12 +174,6 @@ ENDPROC(cpu_resume_arm) 
ENDPROC(cpu_resume_no_hyp)

#endif



	.align 2

_sleep_save_sp:

	.long	sleep_save_sp - .

mpidr_hash_ptr:

	.long	mpidr_hash - .			@ mpidr_hash struct offset



	.data

	.align	2

	.type	sleep_save_sp, #object

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